Influence of zinc molybdenum phosphate pigment on coatings performance studied by electrochemical methods

The effect of the addition of the zinc molybdenum phosphate pigment, on the corrosion resistance properties of powder coating on steel, has been investigated by means of different electrochemical methods: electrochemical impedance spectroscopy (EIS) and the accelerated cyclic electrochemical technique (ACET). Anticorrosive properties obtained from both techniques showed similar results. Powder coatings incorporating this pigment have shown better performance which is attributed to both barrier properties enhancement and inhibition action of the pigment. This behavior can be correlated to the results obtained in the pigment extract study (polarization test and EIS). Finally, salt fog spray test was performed to confirm the electrochemical tests results.